HONOLULU (KHON2) — Climatologically speaking, the last two weeks of August are the peak for the Pacific hurricane season and we are certainly seeing heightened activity as we head into those weeks. Over the weekend, two tropical storms formed in the Eastern Pacific. Fernanda became a tropical storm first, but it was Tropical Storm Greg that entered the Central Pacific basin first.
Tropical Storm Greg had sustained winds of 40 mph at 5 a.m. Monday morning and was moving west at 13 mph. Greg will take a similar path as Hurricane Dora did last week with strong high pressure to the north, as we saw last week.
There are two very significant differences between the Dora situation last week and Greg. First, Greg is forecast to remain a tropical storm over the next few days as it passes well to the south of Hawaii. Second, the high pressure center to the north is not as organized and it is situated a bit farther north and not moving to the west as in sync as last week’s high did with Dora. These key differences between Dora and Greg mean that the winds should not be nearly as strong as the winds we had when Dora passed to the south of Hawaii, which caused the Maui fires to spread so fast.
It is worth noting, however, that the intensity forecasts from the tropical cyclone models in the Pacific this hurricane season have not been very reliable. Therefore, there is a chance that Greg may be stronger than its current forecast. However, the winds are still not expected to be as strong as the winds associated with Hurricane Dora were last week. It will be breezy, but as of now, a Red Flag Warning is not expected. Even though it will not be as windy as it was when Dora passed last week, it will remain extremely dry on leeward sides of the state, and there is a continuing threat of fires developing and/or spreading relatively fast. With no significant rain expected for at least several days, residents should be very careful and aware of the dry conditions, as well as the threat of fire.
Hurricane Fernanda also developed over the weekend and rapidly intensified. At 5 a.m. Monday morning, Fernanda had sustained winds of 130 mph which makes it a weak category 4 hurricane. Fernanda was moving west slowly at 8 mph. Fernanda is expected to strengthen to 145 mph sustained winds by 5 p.m. Monday evening, then it is expected to weaken Tuesday as it moves over cooler water. After that, the National Hurricane Center’s (NHC’s) forecast track for Fernanda has it on a westerly track, weakening rapidly. As a matter of fact, their forecast has Fernanda becoming a tropical storm with 70 mph sustained winds by Wednesday afternoon. NHC then has it weakening to a post-tropical low by Friday before it even crosses into the Central Pacific basin. Hopefully NHC’s forecast holds true and Fernanda weakens before it gets near Hawaii.
So far this year, intensity forecasts from tropical cyclone models in the Pacific have not performed very well. Hurricane Dora was repeatedly forecast to weaken last week yet it did not for several days. As a matter of fact, it strengthened more than once after it was forecast to weaken. Given this uncertainty, and the fact that we are moving into the peak of the Pacific hurricane season in an El Nino year, Hawaii residents are encouraged to remain prepared and continuously monitor the forecast.
There is also a 50% chance that another tropical cyclone over the next 48 hours and a 70% chance it will form in the next seven days. If that tropical cyclone becomes a tropical storm, which it is expected to do, it will be named “Hilary”. That tropical cyclone is also expected to rapidly intensify into a major hurricane, but the long-range models are showing it staying in the Eastern Pacific basin, moving relatively parallel to the Mexican coast. Beyond that, yet another hurricane may form in the Eastern Pacific, possibly as soon as next Tuesday. If that storm comes to fruition and becomes a tropical storm, it will be named “Irwin”.
